Knud Lundberg was a highly versatile athlete and person. He represented the Danish national team in football (soccer), handball and basketball, winning Danish national championships in all three sports. He was capped 39 times for Denmark in football, scoring 10 goals from 1943-56. He was capped 23 times in handball and 21 in basketball. He played his football career with Akademisk Boldklub.
In his non-sporting life, Lundberg studied medicine and sports. He worked as a sports journalist, and was the first sports editor of the Danish newspaper Dagbladet Information. He also spent time as a politician and was a novelist. Among his novels was one on the Olympics, written in 1998, entitled The Olympic Hope, which described the 1996 Olympic 800 metre final. In the novel, Lundberg prophetically described how genetic engineering had a major role in deciding the race.